Photoevaporation from high energy stellar radiation has been thought to drive the dispersal of protoplanetary discs. Different theoretical models have been proposed, but their predictions diverge in terms of the rate and modality at which discs lose their mass, with significant implications for the formation and evolution of planets. In this paper we use disc population synthesis models to interpret recent observations of the lowest accreting protoplanetary discs, comparing predictions from EUV-driven, FUV-driven and X-ray driven photoevaporation models. We show that the recent observational data of stars with low accretion rates (low accretors) point to X-ray photoevaporation as the preferred mechanism driving the final stages of protoplanetary disc dispersal. We also show that the distribution of accretion rates predicted by the X-ray photoevaporation model is consistent with observations, while other dispersal models tested here are clearly ruled out.
{"title":"Lowest accreting protoplanetary discs consistent with X-ray photoevaporation driving their final dispersal","authors":"B. Ercolano, G. Picogna, Kristina Monsch","doi":"10.1093/mnrasl/slad123","DOIUrl":"https://doi.org/10.1093/mnrasl/slad123","url":null,"abstract":"\u0000 Photoevaporation from high energy stellar radiation has been thought to drive the dispersal of protoplanetary discs. Different theoretical models have been proposed, but their predictions diverge in terms of the rate and modality at which discs lose their mass, with significant implications for the formation and evolution of planets. In this paper we use disc population synthesis models to interpret recent observations of the lowest accreting protoplanetary discs, comparing predictions from EUV-driven, FUV-driven and X-ray driven photoevaporation models. We show that the recent observational data of stars with low accretion rates (low accretors) point to X-ray photoevaporation as the preferred mechanism driving the final stages of protoplanetary disc dispersal. We also show that the distribution of accretion rates predicted by the X-ray photoevaporation model is consistent with observations, while other dispersal models tested here are clearly ruled out.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87687162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The tera-electronvolt (TeV) light curve of gamma-ray burst (GRB) 221009A exhibits an unprecedentedly rapid rise at its start. This phenomenon could be due to the strong absorption of photons and electrons within the emitting region. As the external shock expands outward and the radius increases, the volume of matter also grows, resulting in a gradual reduction of the optical depth for TeV photons. We investigate several potential explanations for the early TeV light curves. We calculate the optical depth for TeV photons, considering both annihilation with lower-energy photons in the external shock and their scattering by electrons generated through the cascading of the TeV emission. Even under the favorable assumptions, we have determined that the optical depths for these processes are orders of magnitude too small to explain the observed light curve. Additional sources of absorbers, including electrons in the ejecta or external shock, also do not result in sufficient optical depths. Hence, the cause behind the early peculiar TeV light curve remains unclear.
伽马射线暴（GRB）221009A的太电子伏特（TeV）光曲线在开始时出现了前所未有的快速上升。这种现象可能是由于发射区域对光子和电子的强烈吸收。随着外部冲击向外扩展，半径增大，物质体积也随之增大，导致 TeV 光子的光学深度逐渐减小。我们研究了早期 TeV 光曲线的几种潜在解释。我们计算了 TeV 光子的光学深度，同时考虑了与外部冲击中低能光子的湮灭以及 TeV 辐射级联产生的电子对它们的散射。即使在有利的假设条件下，我们也确定这些过程的光学深度太小，无法解释观测到的光曲线。其他吸收源，包括喷出物或外部冲击中的电子，也不会产生足够的光学深度。因此，早期奇特的 TeV 光曲线背后的原因仍不清楚。
{"title":"What absorbs the early TeV photons of GRB 221009A?","authors":"Jun Shen, Y. Zou, A. Chen, Duan Gao","doi":"10.1093/mnrasl/slad188","DOIUrl":"https://doi.org/10.1093/mnrasl/slad188","url":null,"abstract":"The tera-electronvolt (TeV) light curve of gamma-ray burst (GRB) 221009A exhibits an unprecedentedly rapid rise at its start. This phenomenon could be due to the strong absorption of photons and electrons within the emitting region. As the external shock expands outward and the radius increases, the volume of matter also grows, resulting in a gradual reduction of the optical depth for TeV photons. We investigate several potential explanations for the early TeV light curves. We calculate the optical depth for TeV photons, considering both annihilation with lower-energy photons in the external shock and their scattering by electrons generated through the cascading of the TeV emission. Even under the favorable assumptions, we have determined that the optical depths for these processes are orders of magnitude too small to explain the observed light curve. Additional sources of absorbers, including electrons in the ejecta or external shock, also do not result in sufficient optical depths. Hence, the cause behind the early peculiar TeV light curve remains unclear.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139349835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Galaxy clusters are located at the nodes of cosmic filaments and therefore host a lot of hydrodynamical activity. However, cool core clusters are considered to be relatively relaxed systems without much merging activity. The Abell 85 cluster is a unique example where the cluster hosts both a cool core and multiple ongoing merging processes. In this work, we used 700 MHz uGMRT as well as MeerKAT L-band observations, carried out as part of the MGCLS, of the Abell 85. We reconfirm the presence of a minihalo in the cluster centre at 700MHz that was recently discovered in MGCLS. Furthermore, we discovered a radio bridge connecting the central minihalo and the peripheral radio phoenix. The mean surface brightness, size and flux density of the bridge at 700 MHz is found to be ∼0.14 μJy/arcsec2, ∼220 kpc and ∼4.88 mJy, respectively, with a spectral index of $alpha _{700}^{1.28} = -0.92$. Although the origin of the seed relativistic electrons is still unknown, turbulent re-acceleration caused by both the spiralling sloshing gas in the intracluster medium (ICM) and the post-shock turbulence from the outgoing merging shock associated with the phoenix formation may be responsible for the bridge.
{"title":"A radio bridge connecting the minihalo and phoenix in the Abell 85 cluster","authors":"R. Raja, M. Rahaman, A. Datta, O. Smirnov","doi":"10.1093/mnrasl/slad117","DOIUrl":"https://doi.org/10.1093/mnrasl/slad117","url":null,"abstract":"\u0000 Galaxy clusters are located at the nodes of cosmic filaments and therefore host a lot of hydrodynamical activity. However, cool core clusters are considered to be relatively relaxed systems without much merging activity. The Abell 85 cluster is a unique example where the cluster hosts both a cool core and multiple ongoing merging processes. In this work, we used 700 MHz uGMRT as well as MeerKAT L-band observations, carried out as part of the MGCLS, of the Abell 85. We reconfirm the presence of a minihalo in the cluster centre at 700MHz that was recently discovered in MGCLS. Furthermore, we discovered a radio bridge connecting the central minihalo and the peripheral radio phoenix. The mean surface brightness, size and flux density of the bridge at 700 MHz is found to be ∼0.14 μJy/arcsec2, ∼220 kpc and ∼4.88 mJy, respectively, with a spectral index of $alpha _{700}^{1.28} = -0.92$. Although the origin of the seed relativistic electrons is still unknown, turbulent re-acceleration caused by both the spiralling sloshing gas in the intracluster medium (ICM) and the post-shock turbulence from the outgoing merging shock associated with the phoenix formation may be responsible for the bridge.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"112 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75678954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Hubrig, S. Jarvinen, J. Alvarado‐Gómez, I. Ilyin, M. Scholler
Numerous δ Sct and γ Dor pulsators are identified in the region of the Hertzsprung-Russell diagram that is occupied by chemically peculiar magnetic Ap stars. The connection between δ Sct and γ Dor pulsations and the magnetic field in Ap stars is however not clear: theory suggests for magnetic Ap stars some critical field strengths for pulsation mode suppression by computing the magnetic damping effect for selected p and g modes. To test these theoretical considerations, we obtained PEPSI spectropolarimetric snapshots of the typical Ap star HD 340577, for which δ Sct-like pulsations were recently detected in TESS data, and the γ Dor pulsator HR 8799, which is a remarkable system with multiple planets and two debris disks. Our measurements reveal the presence of a magnetic field with a strength of several hundred Gauss in HD 340577. The measured mean longitudinal field would be the strongest field measured so far in a δ Sct star if the pulsational character of HD 340577 is confirmed spectroscopically. No magnetic field is detected in HR 8799.
{"title":"Searching for magnetic fields in pulsating A-type stars: the discovery of a strong field in the probable δ Sct star HD 340577 and a null result for the γ Dor star HR 8799","authors":"S. Hubrig, S. Jarvinen, J. Alvarado‐Gómez, I. Ilyin, M. Scholler","doi":"10.1093/mnrasl/slad116","DOIUrl":"https://doi.org/10.1093/mnrasl/slad116","url":null,"abstract":"\u0000 Numerous δ Sct and γ Dor pulsators are identified in the region of the Hertzsprung-Russell diagram that is occupied by chemically peculiar magnetic Ap stars. The connection between δ Sct and γ Dor pulsations and the magnetic field in Ap stars is however not clear: theory suggests for magnetic Ap stars some critical field strengths for pulsation mode suppression by computing the magnetic damping effect for selected p and g modes. To test these theoretical considerations, we obtained PEPSI spectropolarimetric snapshots of the typical Ap star HD 340577, for which δ Sct-like pulsations were recently detected in TESS data, and the γ Dor pulsator HR 8799, which is a remarkable system with multiple planets and two debris disks. Our measurements reveal the presence of a magnetic field with a strength of several hundred Gauss in HD 340577. The measured mean longitudinal field would be the strongest field measured so far in a δ Sct star if the pulsational character of HD 340577 is confirmed spectroscopically. No magnetic field is detected in HR 8799.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73329231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J van den Eijnden, L Sidoli, M Díaz Trigo, N Degenaar, I El Mellah, F Fürst, V Grinberg, P Kretschmar, S Martínez-Núñez, J C A Miller-Jones, K Postnov, T D Russell
ABSTRACT Neutron stars accreting from OB supergiants are often divided between persistently and transiently accreting systems, called supergiant X-ray binaries (SgXBs) and supergiant fast X-ray transients (SFXTs). This dichotomy in accretion behaviour is typically attributed to systematic differences in the massive stellar wind, binary orbit, or magnetic field configuration, but direct observational evidence for these hypotheses remains sparse. To investigate their stellar winds, we present the results of pilot 100-GHz observations of one SFXT and one SgXB with the Northern Extended Millimetre Array. The SFXT, IGR J18410-0535, is detected as a point source at 63.4 ± 9.6 μJy, while the SgXB, IGR J18410-0535 remains undetected. Radio observations of IGR J18410-0535 imply a flat or inverted low-frequency spectrum, arguing for wind emission and against non-thermal flaring. Due to the uncertain SFXT distance, however, the observations do not necessarily imply a difference between the wind properties of the SFXT and SgXB. We compare the mm constraints with other HMXBs and isolated OB supergiants, before considering how future mm campaigns can constrain HMXB wind properties by including X-ray measurements. Specifically, we discuss caveats and future steps to successfully measure wind mass-loss rates and velocities in HMXBs with coordinated mm, radio, and X-ray campaigns.
{"title":"The first mm detection of a neutron star high-mass X-ray binary","authors":"J van den Eijnden, L Sidoli, M Díaz Trigo, N Degenaar, I El Mellah, F Fürst, V Grinberg, P Kretschmar, S Martínez-Núñez, J C A Miller-Jones, K Postnov, T D Russell","doi":"10.1093/mnrasl/slad130","DOIUrl":"https://doi.org/10.1093/mnrasl/slad130","url":null,"abstract":"ABSTRACT Neutron stars accreting from OB supergiants are often divided between persistently and transiently accreting systems, called supergiant X-ray binaries (SgXBs) and supergiant fast X-ray transients (SFXTs). This dichotomy in accretion behaviour is typically attributed to systematic differences in the massive stellar wind, binary orbit, or magnetic field configuration, but direct observational evidence for these hypotheses remains sparse. To investigate their stellar winds, we present the results of pilot 100-GHz observations of one SFXT and one SgXB with the Northern Extended Millimetre Array. The SFXT, IGR J18410-0535, is detected as a point source at 63.4 ± 9.6 μJy, while the SgXB, IGR J18410-0535 remains undetected. Radio observations of IGR J18410-0535 imply a flat or inverted low-frequency spectrum, arguing for wind emission and against non-thermal flaring. Due to the uncertain SFXT distance, however, the observations do not necessarily imply a difference between the wind properties of the SFXT and SgXB. We compare the mm constraints with other HMXBs and isolated OB supergiants, before considering how future mm campaigns can constrain HMXB wind properties by including X-ray measurements. Specifically, we discuss caveats and future steps to successfully measure wind mass-loss rates and velocities in HMXBs with coordinated mm, radio, and X-ray campaigns.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135745286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanjaya Paudel, Pierre-Alain Duc, Sungsoon Lim, Mélina Poulain, Francine R Marleau, Oliver Müller, Rubén Sánchez-Janssen, Rebecca Habas, Patrick R Durrell, Nick Heesters, Daya Nidhi Chhatkuli, Suk-Jin Yoon
We study a compact nucleus embedded in an early-type dwarf galaxy, MATLAS-167, which is in the process of disruption by the tidal force of the neighboring giant S0 galaxy, NGC 936, in a group environment. Using the imaging data of the MATLAS survey, we analyze the stellar tidal tail of MATLAS-167 and its central compact nucleus, designated as NGC 936_UCD. We find that NGC 936_UCD has a luminosity of M$_{g}$ = $-$11.43$pm$0.01 mag and a size of 66.5$pm$17 pc, sharing the global properties of Ultra Compact Dwarf galaxies (UCDs) but significantly larger and brighter compared to the typical UCD populations observed in the Virgo cluster. By integrating the total luminosity of both the tidal stream and MATLAS-167, we estimate that the disrupted dwarf progenitor possesses a luminosity of M$_{g}$ = $-$15.92$pm$0.06 mag, a typical bright dE luminosity. With the help of the optical spectrum observed by the SDSS survey, we derive the simple stellar population properties of NGC 936_UCD: a light-weighted age of 5.6$pm$0.7 Gyr and metallicity of [Z/H] = $-$0.83$pm$0.3 dex. Our findings suggest that tidal threshing is a possible formation mechanism of bright UCD populations in close proximity to giant galaxies.
{"title":"The creation of a massive UCD by tidal threshing from NGC 936","authors":"Sanjaya Paudel, Pierre-Alain Duc, Sungsoon Lim, Mélina Poulain, Francine R Marleau, Oliver Müller, Rubén Sánchez-Janssen, Rebecca Habas, Patrick R Durrell, Nick Heesters, Daya Nidhi Chhatkuli, Suk-Jin Yoon","doi":"10.1093/mnrasl/slad126","DOIUrl":"https://doi.org/10.1093/mnrasl/slad126","url":null,"abstract":"We study a compact nucleus embedded in an early-type dwarf galaxy, MATLAS-167, which is in the process of disruption by the tidal force of the neighboring giant S0 galaxy, NGC 936, in a group environment. Using the imaging data of the MATLAS survey, we analyze the stellar tidal tail of MATLAS-167 and its central compact nucleus, designated as NGC 936_UCD. We find that NGC 936_UCD has a luminosity of M$_{g}$ = $-$11.43$pm$0.01 mag and a size of 66.5$pm$17 pc, sharing the global properties of Ultra Compact Dwarf galaxies (UCDs) but significantly larger and brighter compared to the typical UCD populations observed in the Virgo cluster. By integrating the total luminosity of both the tidal stream and MATLAS-167, we estimate that the disrupted dwarf progenitor possesses a luminosity of M$_{g}$ = $-$15.92$pm$0.06 mag, a typical bright dE luminosity. With the help of the optical spectrum observed by the SDSS survey, we derive the simple stellar population properties of NGC 936_UCD: a light-weighted age of 5.6$pm$0.7 Gyr and metallicity of [Z/H] = $-$0.83$pm$0.3 dex. Our findings suggest that tidal threshing is a possible formation mechanism of bright UCD populations in close proximity to giant galaxies.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135745290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenta Hotokezaka, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas
ABSTRACT The late-time spectra of the kilonova AT 2017gfo associated with GW170817 exhibit a strong emission line feature at $2.1, {rm mu m}$. The line structure develops with time and there is no blueshifted absorption feature in the spectra, suggesting that this emission line feature is produced by electron collision excitation. We attribute the emission line to a fine structure line of Tellurium (Te) III, which is one of the most abundant elements in the second r-process peak. By using a synthetic spectral modelling including fine structure emission lines with the solar r-process abundance pattern beyond the first r-process peak, i.e. atomic mass numbers A ≳ 88, we demonstrate that [Te iii] $2.10, rm mu m$ is indeed expected to be the strongest emission line in the near infrared region. We estimate that the required mass of Te iii is ∼10−3 M⊙, corresponding to the merger ejecta of 0.05 M⊙, which is in agreement with the mass estimated from the kilonova light curve.
与GW170817相关的千新星AT 2017gfo的晚时光谱在$2.1，{rm mu m}$处表现出强烈的发射谱线特征。谱线结构随时间发展，光谱中没有蓝移吸收特征，表明这种发射谱线特征是由电子碰撞激发产生的。我们将发射线归因于碲(Te) III的精细结构线，它是第二个r过程峰中最丰富的元素之一。通过一个包含太阳r过程丰度模式超过第一个r过程峰(即原子质量数a > 88)的精细结构发射谱线的合成光谱模型，我们证明了[Te iii] $2.10， rm mu m$确实是近红外区域最强的发射谱线。我们估计teiii的所需质量为~ 10−3 M⊙，对应于0.05 M⊙的合并抛射，这与从千新星光曲线估计的质量一致。
{"title":"Tellurium emission line in kilonova AT 2017gfo","authors":"Kenta Hotokezaka, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas","doi":"10.1093/mnrasl/slad128","DOIUrl":"https://doi.org/10.1093/mnrasl/slad128","url":null,"abstract":"ABSTRACT The late-time spectra of the kilonova AT 2017gfo associated with GW170817 exhibit a strong emission line feature at $2.1, {rm mu m}$. The line structure develops with time and there is no blueshifted absorption feature in the spectra, suggesting that this emission line feature is produced by electron collision excitation. We attribute the emission line to a fine structure line of Tellurium (Te) III, which is one of the most abundant elements in the second r-process peak. By using a synthetic spectral modelling including fine structure emission lines with the solar r-process abundance pattern beyond the first r-process peak, i.e. atomic mass numbers A ≳ 88, we demonstrate that [Te iii] $2.10, rm mu m$ is indeed expected to be the strongest emission line in the near infrared region. We estimate that the required mass of Te iii is ∼10−3 M⊙, corresponding to the merger ejecta of 0.05 M⊙, which is in agreement with the mass estimated from the kilonova light curve.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135598415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H Middleton, A Sesana, S Chen, A Vecchio, W Del Pozzo, P A Rosado
{"title":"Correction to: Massive black hole binary systems and the NANOGrav 12.5 yr results","authors":"H Middleton, A Sesana, S Chen, A Vecchio, W Del Pozzo, P A Rosado","doi":"10.1093/mnrasl/slad087","DOIUrl":"https://doi.org/10.1093/mnrasl/slad087","url":null,"abstract":"","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135697745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S Fijma, N Castro Segura, N Degenaar, C Knigge, N Higginbottom, J V Hernández Santisteban, T J Maccarone
ABSTRACT Accreting low-mass X-ray binaries (LMXBs) are capable of launching powerful outflows such as accretion disc winds. In disc winds, vast amounts of material can be carried away, potentially greatly impacting the binary and its environment. Previous studies have uncovered signatures of disc winds in the X-ray, optical, near-infrared, and recently even the ultraviolet (UV) band, predominantly in LMXBs with large discs (Porb ≥ 20 h). Here, we present the discovery of transient UV outflow features in UW CrB, a high-inclination (i ≥ 77°) neutron star LMXB (NS-LMXB) with an orbital period of only Porb ≈ 111 min. We present P-Cygni profiles identified for Si iv 1400 Å and tentatively for N v 1240 Å in one 15 min exposure, which is the only exposure covering orbital phase ϕ ≈ 0.7–0.8, with a velocity of ≈1500 km s−1. We show that due to the presence of blackbody emission from the neutron star surface and/or boundary layer, a thermal disc wind can be driven despite the short Porb, but explore alternative scenarios as well. The discovery that thermal disc winds may occur in NS-LMXBs with Porb as small as ≈111 min, and can potentially be transient on time-scales as short as ≈15 min, warrants further observational and theoretical work.
吸积的低质量x射线双星(lmxb)能够发射强大的外流，如吸积盘风。在圆盘风中，大量的物质可以被带走，潜在地极大地影响双星及其环境。先前的研究已经发现了签名的圆盘风x射线光学、近红外,甚至最近紫外线(UV)乐队,主要在LMXB大光盘(Porb≥20 h)。在这里,我们报告的发现瞬态紫外线流出特性在威斯康辛大学CrB,一个高倾角(我≥77°)中子星LMXB (NS-LMXB)的轨道周期只有Porb≈111分钟。我们现在P-Cygni概要文件为第四Si 1400和初步确定N v 1240一分之一15分钟曝光,这是唯一覆盖轨道相位φ≈0.7-0.8，速度≈1500 km s−1的曝光。我们表明，由于来自中子星表面和/或边界层的黑体发射的存在，尽管短Porb也可以驱动热盘风，但也探索了其他情景。发现热盘风可能发生在ns - lmxb中，其波速小至≈111分钟，并且可能在短至≈15分钟的时间尺度上是短暂的，这需要进一步的观测和理论工作。
{"title":"A transient ultraviolet outflow in the short-period X-ray binary UW CrB","authors":"S Fijma, N Castro Segura, N Degenaar, C Knigge, N Higginbottom, J V Hernández Santisteban, T J Maccarone","doi":"10.1093/mnrasl/slad125","DOIUrl":"https://doi.org/10.1093/mnrasl/slad125","url":null,"abstract":"ABSTRACT Accreting low-mass X-ray binaries (LMXBs) are capable of launching powerful outflows such as accretion disc winds. In disc winds, vast amounts of material can be carried away, potentially greatly impacting the binary and its environment. Previous studies have uncovered signatures of disc winds in the X-ray, optical, near-infrared, and recently even the ultraviolet (UV) band, predominantly in LMXBs with large discs (Porb ≥ 20 h). Here, we present the discovery of transient UV outflow features in UW CrB, a high-inclination (i ≥ 77°) neutron star LMXB (NS-LMXB) with an orbital period of only Porb ≈ 111 min. We present P-Cygni profiles identified for Si iv 1400 Å and tentatively for N v 1240 Å in one 15 min exposure, which is the only exposure covering orbital phase ϕ ≈ 0.7–0.8, with a velocity of ≈1500 km s−1. We show that due to the presence of blackbody emission from the neutron star surface and/or boundary layer, a thermal disc wind can be driven despite the short Porb, but explore alternative scenarios as well. The discovery that thermal disc winds may occur in NS-LMXBs with Porb as small as ≈111 min, and can potentially be transient on time-scales as short as ≈15 min, warrants further observational and theoretical work.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135745791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The cold dark matter (CDM) paradigm provides a remarkably good description of the Universe’s large-scale structure. However, some discrepancies exist between its predictions and observations at very small sub-galactic scales. To address these issues, the consideration of a strong interaction between dark matter particles and dark radiation emerges as an intriguing alternative. In this study, we explore the constraints on those models using joint observations of Cosmic Microwave Background (CMB) and Quasars absorption spectra with our previously built parameter estimation package CosmoReionMC. At 2-σ confidence limits, this analysis rules out the strongly interacting Dark Matter - Dark Radiation models within the recently proposed ETHOS framework, representing the most stringent constraint on those models to the best of our knowledge. Future research using a 21-cm experiment holds the potential to reveal stronger constraints or uncover hidden interactions within the dark sector.
{"title":"Ruling out strongly interacting Dark Matter–Dark Radiation models from joint observations of Cosmic Microwave Background and Quasar absorption spectra","authors":"Atrideb Chatterjee, Sourav Mitra, Amrita Banerjee","doi":"10.1093/mnrasl/slad193","DOIUrl":"https://doi.org/10.1093/mnrasl/slad193","url":null,"abstract":"The cold dark matter (CDM) paradigm provides a remarkably good description of the Universe’s large-scale structure. However, some discrepancies exist between its predictions and observations at very small sub-galactic scales. To address these issues, the consideration of a strong interaction between dark matter particles and dark radiation emerges as an intriguing alternative. In this study, we explore the constraints on those models using joint observations of Cosmic Microwave Background (CMB) and Quasars absorption spectra with our previously built parameter estimation package CosmoReionMC. At 2-σ confidence limits, this analysis rules out the strongly interacting Dark Matter - Dark Radiation models within the recently proposed ETHOS framework, representing the most stringent constraint on those models to the best of our knowledge. Future research using a 21-cm experiment holds the potential to reveal stronger constraints or uncover hidden interactions within the dark sector.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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